Physician well-being is associated with benefits for physicians, patients, and health care systems. Well-being encompasses many inter-related attributes, including but not limited to resilience, fulfillment, joy in work, and burnout. Among these, burnout has been studied most widely, and has been found to be more frequent among medical trainees and professionals than in the general population. Burnout has been associated with physician depression and suicidality, which are also more frequent among physicians than the general population. The negative effects of burnout include decreased patient satisfaction, increased medical errors, and increased costs. Physician burnout has been associated with both organization-level drivers that contribute to an imbalance between resources and workload for physicians, and individual-level drivers related to resilience practices and attitudes. This paper reviews the literature on the epidemiology, drivers, and implications of physician burnout.